Conexant Systems, Inc.

Newport Fab, LLC

David Feiler

Bin Zhao

Maureen R Brongo

Qizhi Liu

Q Z Liu

Phil N Sherman

Method for selective fabrication of high capacitance density areas in a low dielectric constant material and related structure are disclosed. In one embodiment, a first area of a dielectric layer is covered, for example with photoresist, while a second area of the dielectric layer is exposed to a dielectric conversion source such as E-beams, I-beams, oxygen plasma, or an appropriate chemical. The exposure causes the dielectric constant of the dielectric layer in the second area to increase. A number of capacitor trenches are etched in the second area of the dielectric. The capacitor trenches are then filled with an appropriate metal, such as copper, and a chemical mechanical polish is performed. The second area in which the capacitor trenches have been etched and filled has a higher capacitance density relative to the first area. In another embodiment, the exposure to the dielectric conversion source is not performed until after the chemical mechanical polish has been performed. In yet another embodiment, a blanket layer of metal, such as aluminum, is first deposited. The blanket layer of metal is then etched to form metal lines. Then a gap fill dielectric is utilized to fill the gaps between the remaining metal lines. A first area of the gap fill dielectric is then covered and a second area of the gap fill dielectric is exposed to a dielectric conversion source. After exposure to the dielectric conversion source, the dielectric constant of the gap fill dielectric in the second area increases. The metal lines in the second area can then be used as capacitor electrodes of a high density capacitor.

Selective fabrication of high capacitance density areas in a low dielectric constant material

Method for selective fabrication of high capacitance density areas in a low dielectric constant material and related structure are disclosed. In one embodiment, a first area of a dielectric layer is covered while a second area of the dielectric layer is exposed to a dielectric conversion source. The exposure causes the dielectric constant of the dielectric layer in the second area to increase. A number of interconnect trenches are etched in the first area of the dielectric and a number of capacitor trenches are etched in the second area of the dielectric. The interconnect trenches and the capacitor trenches are then filled with an appropriate metal, such as copper, and a chemical mechanical polish is performed. The second area in which the capacitor trenches have been etched and filled has a higher capacitance density relative to the first area.

Method for selective fabrication of high capacitance density areas in a low dielectric constant material

Method for dual damascene metallization of semiconductor workpieces which uses a process for creating an etch stop in an insulator thereby eliminating the need for deposition of an etch stop layer. Electron beam exposure is used to cure the insulator, or material having a low dielectric constant. Application of the electron beam to the low dielectric constant material converts the topmost layer of the low dielectric constant material to an etch stop layer, while rapid thermal heating cures the remainder of the low dielectric constant material. Creation of an etch stop layer in the low dielectric constant material can also be achieved by curing the low dielectric constant material using ion implantation.

Method for dual damascene process using electron beam and ion implantation cure methods for low dielectric constant materials

The present invention relates to the reduction of poisoned vias in a submicron process technology semiconductor wafer by reducing the occurrence of over-etched vias through the inclusion of an etch-stop layer. Vias are created to connect conductive portions of a semiconductor wafer and if the vias are over-etched, the connection may be poor. In order to prevent the over-etching of vias, a three-step etch process is completed on a semiconductor wafer having an insulating layer, an etch-stop layer, a low dielectric constant layer, a conductive layer and a foundation layer. A via is first non-selectively etched such that the etch terminates within the insulating layer. The via is subsequently selectively etched such that the etch terminates at the etch-stop layer. Lastly, the via is again non-selectively etched through the etch-stop layer and the low dielectric constant layer such that the etch terminates at the conductive layer.

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Irvine, CA, United States of America

David Feiler